P. tenuifolia Willd. And P. sibirica L. are traditional Chinese herb medicines. Generally the root as a whole or only cortex of the root of which are taken as a medicine useful in tranquilizing a patient, treating coughing and releasing inflammation. It was reported by Koo et al. that an aqueous extract of polygala tenuifolia WILLDENOW (polygalaceae) root may prevent the ethanol-induced cytoxicity in Hep G2 cells through inhibitition of the apoptosis of Hep G2 cells [Koo H N, Jeong H J, Kim K R, Kim J C, Kim K S, Kang B K, Kim H M and Kim J J. Immunopharmacology & Immunotoxicology. 22(3): 531-44, 2000]. Kim et al. also reported that an aqueous extract of polygala tenuifolia root may inhibit tumor necrosis factor-alpha secretion by inhibiting interleukin-1 secretion, and has an anti-inflammatory activity on the central nervous system [Kim H M, Lee E H, Na H J, Lee S B, Shin T Y, Lyu Y S, Kim N S and Nomura S. Journal of Ethnopharmacology. 61(3): 201-8, 1998]. Furthermore, it was reported that euxanthone may be one of the neuropharmacological active compounds in the medicinal plant polygala audata [Mak N K, Li W K, Zhang M, Wong R N, Tai L S, Yung K K and Leung H W. Life Sciences. 66(4): 347-54, 2000]. The saponins of polygala were reported having the potential to be used as vaccine adjuvants to increase specific immune responses [Estrada A, Katselis G S, Laarveld B and Barl B. Comparative Immunology, Microbiology & Infectious Diseases. 23(1): 27-43, 2000] and having significant immunological properties [Desbene S, Hanquet B, Shoyama Y, Wagner H and Lacaille-Dubois M A. Journal of Natural Products. 62(6): 923-6, 1999]. Other pharmacological activities can also be found in the literature, but none of them suggests an anti-depression activity.